1994 Ford Explorer 04 Explorer engine in a 88 Ranger

Tiny
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  • 1994 FORD EXPLORER
Engine Performance problem
1994 Ford Explorer 6 cyl Four Wheel Drive Manual?Broke miles

Hey guys, I have a 2004 ford explorer 4.0 v6 engine and dash in an 88 ranger with ranger drive train. Put together to be used as a mud truck for the past few years and has been beaten up on but dosent want to die. It drives pretty good for an old beat up truck
**My concern is that the engine has**
(1)very slight (idle mainly) misfire symptom,
(2)hesitates when accelerating from its set 600 rpm idle but pretty much smooths out after 2000- but no real hesitation accellarating from about 1000 rpm on up, (3)i THINK that most of the problem occurs once the check engine lite comes on(usually about a minute after starting).
(4)intake manifold is loaded inside with black greasy carbon stuff
**things I did to try and fix it so far**
(1) I changed the plugs, wires, and coil(checked and double checked wiring configuration so thats not it)(2) sprayed fuel injector/throttle body cleaner in throat(while off and while running-and wasnt really able to remove intake hose thing too far off throttle body throat without it stalling
(3)removed air filter-ran the engine-and reinstalled it(no change)
(4)removed MAF sensor plug while it was running and didnt hear a difference even when I revved up th motor(i think its called that-sensor right there with air filter?)
`really strange that it would stall when I pulled the rubber intake off the throttle body but not when I disonnected that sensor
Please help!- I dont want to dump more useless money into this old mud truck
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Wednesday, May 6th, 2009 AT 8:50 PM

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Tiny
JGAROFALO
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Do you have the 2004 computer, wiring, and sensors in the Ranger? Is it the correct computer for the type of transmission you have? Is this a "new" symptom, or has it been this way since installation?

Next, I suggest that you put some diagnostics on the engine. This has the sound of a bad mass air flow sensor. Also, you should never clean the throttle body. Cleaning it will cause idle problems and hesitations.
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Sunday, May 10th, 2009 AT 7:44 AM
Tiny
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In addition my fuel pump is an aftermarket electric external one being that this car origionally had a carbuerator and mechanical fuel pump it needed this different one. I checked the fuel pressure and factory(vaccum connected) pressure should be between 30-45 psi idle for this engine and I had 30 psi with the vac still hooked up to regulator, didnt check w/o hookup yet but it runs the same without it hooked up. Could that still be it, or maybe a bad injector or regulator? I also stalled out and to get going I put 2 gallons gas thinking that would get me going, but I had to disconnect fuel pump and turn over the engine and finally fuel started coming out from pump after about 10 seconds with the help of boosting the engine with a shot of either into the throttle body. Does that tell u anything. The computer scanning just gave automatic transmission codes(which was for the car this motor was origionally in)as well as one "EGR valve" code?-All with car on/engine off
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Monday, May 11th, 2009 AT 6:19 PM
Tiny
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You should definitely have more pressure in the fuel system. The system is designed to have a constant pressure across the injectors. With vacuum, the pressure will be lower, without vacuum, it should be higher. The reason for the constant pressure is for the PCM to calculate the proper duty cycle for the injectors to dispense the correct amout of fuel - without adding more variables.

Probably the reason you had to prime the system is that the PCM is apparently not controlling the fuel pump relay. The PCM is programmed to run the pump for a few seconds on power-up and turn it off until it "sees" an ignition signal to turn it back on.

The trouble codes you are getting are most likely the result of having a "hybrid" setup that the system was not programmed for. I would suggest that you start by getting a '04 PCM from a stick shift. This will eliminate the transmission codes. The EGR code could be coming from a problem in the wiring.

Keep in mind that the entire SYSTEM was designed and programmed for a different vehicle with a different type of transmission. Your task now is to satisfy the PCM. When the PCM is not happy, it goes into a default programming mode that is essentially a cold engine program. Performance and driveability suffer ein this mode. Simply changing parts is not likely to solve the problem(s).
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Monday, May 11th, 2009 AT 6:37 PM
Tiny
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Lol :). Thanks man, that sounds like were getting somewhere with the troubleshooting process. Very interesting, especially because, well, uh, there is no fuel pump relay in this rig!Lol I dont kno what the guys that built this thing were thinking, but this sounds like I should just make sure what I have is not broken/clogged in the fuel system(regulator, pump, ect.), And maybe put a cheap higher pressure pump in?And if that dosent work its probrably too much money to go any further on this thing huh?Just drive it to the ground? Also if I were to get an 04 manual computer, will it hook up properly to this 88 ranger gearbox? And what kind of 04 manual computer? 4.0L V6 ford anything(whatever that had this motor with a manual trans in 04?)
thanks again for your time helping me with this! I hope you tell me it will be worth it, and the pump could be a possible fix.
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Tuesday, May 12th, 2009 AT 3:48 PM
Tiny
JGAROFALO
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Well, why not start with the easier stuff first.
First thing you need to find is a reasonably priced DIY junkyard. We have them in my neck of the woods, not sure about where you are. Around here, a computer only runs about $10 to 20 if you pull it yourself. Any Explorer or Ranger computer from a 4.0 with stick shift should be OK.

A really good starting point would be to get a Haynes manual for the car that the engine came from. Look at the wiring diagram. You can get a used power distribution box and wire the thing yourself without too much complication. The important things are the PCM power relay and the fuel pump relay. There is a very good reason that the PCM controls the fuel pump - SAFETY! If you were to develop a fuel leak or be involved in a collision that compromised your fuel lines, the PCM will shut off the fuel. Without the relay and the inertia switch, the fuel keeps coming. If you try to restart at that point, without a safety system, you could potentially have the entire contents of the fuel tank leaking all over. One spark, and you have a "towering inferno"!

The loaded question is whether it is worth it. Only you can decide that. You have the potential for a good usable truck that can serve you for many years - assuming the rest of the vehicle is in good shape. Rust and general condition are the main points to consider.

BTW, fuel pressure is very important. The system is designed to operate on a predetermined fuel strategy that is programmed into the PCM. That is why there is a pressure regulator and a high volume/high pressure pump in the original. If you don't have the right pressure, nothing else you do will matter.
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Tuesday, May 12th, 2009 AT 5:11 PM

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